On Saturday, the Prime Minister announced that Greater London would be moving into a new Tier 4 set of restrictions from 00.01 on Sunday morning.
The graphic below, produced by the government, explains what Tier 4 means in practice.
You can find the government's [guidance] in full regarding Tier 4 here.
Like you, I was saddened to hear the news that London has been moved into a Tier 4, in response to a marked increase in the number of COVID cases and hospital admissions over the last week.